Conventionally, an obstacle detected by an apparatus was displayed, on a screen of the apparatus, as a captured image that captures a field around a vehicle, for notifying the user of the danger of the obstacle, for example.
Further, in recent years, the captured image of the obstacle in the near field has detection information superposed thereon when it is displayed on the screen. For example, as disclosed in a Japanese patent document JP-A-2005-45602, the detection information detected by an obstacle detector is translated into a symbolic icon, and the symbolic icon is superposed in the camera captured image of the near field for the display on a monitoring device.
However, the above technique of the obstacle detection has a problem that the user has difficulty in determining which way the obstacle is moving in the captured image. More practically, in the technique in the document JP-A-2005-45602, the detection information is displayed in a superposing manner on the detected obstacle in the captured image only as a symbolic icon that shows a detected distance of the obstacle and a position of the obstacle in a detection area of the detector. Therefore, the user has a hard time to understand whether, for example, the obstacle is moving away from the user's vehicle or is coming closer to the vehicle, thereby having difficulty in finding which way he or she should maneuver.